Bellator MMA (formerly known as "Bellator Fighting Championships") is an American mixed martial arts promotion, and the following is a history of its champions in each weight class. At the time of its inception in 2008, CEO Bjorn Rebney founded Bellator Fighting Championships as a tournament based organization. The inaugural champion for each weight class was determined by the winner of an eight-man tournament. All subsequent title challengers were required to first win an eight-man tournament in a specific weight class in order to earn the right to challenge that division's reigning champion. Dethroned champions were required to re-enter the tournaments in order to attempt to regain their title. Under Bjorn Rebney's sole leadership, Bellator MMA would strictly adhere to these rules during the first four years of its operation. The first changes to this format would begin to appear not long after Viacom, Inc. purchased a controlling stake in the organization. In November 2012, CEO Bjorn Rebney announced the introduction of a "championship rematch clause". This would allow Bellator to schedule an immediate title-fight rematch if officials deemed the fight necessary. The next major change occurred during Bellator's 2013 Summer Series when it was announced that all three tournaments would be shorter, four-man affairs instead of the standard eight. Though originally stated to return to the eight-man only tournaments afterwards, officials instead decided to add two additional four-man tournaments to the existing tournament lineup in an effort to provide a more consistent flow of title challengers for their champions to face. Two additional rule changes would be announced. The first was the "tournament champion replacement clause" introduced in August 2013. This allowed officials to grant title shots to replacement fighters when tournament winners were injured, or otherwise unavailable, through a complex voting and points system. Then, in June 2014, CEO Bjorn Rebney made an announcement stating that any fighter who had previously won a Bellator tournament would maintain permanent eligibility to fight for a title without having to re-enter another tournament. Neither of these changes would ever be implemented, however, as one week later Bellator MMA and its founder and CEO Bjorn Rebney parted ways, bringing about an end to the organization's tournament based model. Current champions Men's championship history Heavyweight World Championship 206 to 265 lbs (93 to 120 kg) Light Heavyweight World Championship 186 to 205 lbs (84 to 93 kg) Middleweight World Championship 171 to 185